Expiration Date Effect on Mechanical and Chemical Properties of Glass Ionomer Cements

V. Zavala-Alonso; R. Jerónimo-Prieto; J. Ramírez-González; G. Romo-Ramírez; M. Goldaracena-Azuara & C. Ochoa-Monreal

Summary

The glass ionomer cements (GICs) is a generic name given to a group of materials widely used in clinical dentistry which if used after the specified expiration date, material properties may be affected. to evaluate the Vickers microhardness, surface morphology and the energy dispersive X-ray microanalysis (EDX), of GICs with different expiration dates that were stored at room temperature. specimens of highly viscous glass ionomer cement (HVGIC) (Ketac Cem and Ketac Molar) and resin-modified glass ionomer cement (RMGIC) (Vitrebond) with different expiration dates (current, close to their expiration and expired) were prepared for Vickers microhardness test and scanning electronic microscopy (SEM) with EDX, measuring 5 mm in diameter and 2 mm length, per the manufacturer’s instructions, in standard cylindrical teflon molds. For the comparison of obtained values, the ANOVA test was used, while Tukey test was used for the multiple comparisons. In all the GICs used, the microhardness decreased as the expiration date approached, finding a significant statistical difference (P<0.05) in Ketac Molar and Vitrebond. SEM sample analysis revealed similar cohesive cracks in all tested materials. The EDX analysis revealed the presence of the elements F, Al and Si in all GICs and Ca only in Ketac Molar and Ketac Cem. The elements were found in a higher atomic percentage in the GICs with an current date and in a lower percentage in those with an expired date. HVGIC and RMGIC with an expiration date finish and that were stored at room temperature, suffer significant physical and chemical changes, which could put doubts its clinical effectiveness.

KEY WORDS: glass ionomer cements, expiration date, mechanical and chemical properties, Vickers micro-hardness, scanning electron microscopy, energy dispersive X-ray microanalysis.

How to cite this article

ZAVALA-ALONSO, V.; JERÓNIMO-PRIETO, R.; RAMÍREZ-GONZÁLEZ, J.; ROMO-RAMÍREZ, G.; GOLDARACENA-AZUARA, M. & OCHOA-MONREAL, C. Expiration date effect on mechanical and chemical properties of glass ionomer cements. Int. J. Odontostomat., 15(2):513-519, 2021.